1. Field of the Invention
This invention relates to a ultrasonically operating transducer device for the measurement of the flow velocity of a fluid in a pipe, comprising two transducers mounted on either side of the pipe and directed obliquely in relation to the direction of the flow, which transducers alternately transmit and receive sonic pulses to and from each other.
2. Discussion of the Related Art
The invention is especially developed in connection with the need for measuring the gas flow in a so-called flare in connection with facilities for exploration and production of hydro carbons, but it is not limited to such a utilization.
There is a need to be able to cover, with one transducer arrangement, a relatively wide range of flow velocities in an accurate manner, while there is also a need for safety, particularly when measuring in hazardous areas.
The transducer devices known today, of the kind mentioned initially, have the disadvantage that the measurable range of velocity is relatively limited. Also, the accuracy of measurement is not always completely satisfactory. In the case of measuring in hazardous areas (for example, where there is a danger of explosion) it is necessary to transmit signals for evaluation to a safety zone. This transmission of signals will often disturb the measurements, because the signals are exposed to electromagnetic influences from the environment during the required transmission through cables.